The Feasibility of a Year-Long Incubation Period Virus

Recently, I've been engrossed in the game Plague Inc., where players create and evolve deadly diseases to wipe out humanity. One of the intriguing questions I pondered during this gameplay is the feasibility of a virus with a one-year or more incubation period that is highly contagious and subsequently mutates into an extremely lethal form after two years. When everyone on Earth has it, would the situation be catastrophic?

Is a Such Virus Feasible?

From a scientific standpoint, the idea of a virus with a one-year incubation period that becomes a highly contagious and extremely lethal mutation after two years is highly unlikely. Viruses do not mutate on command nor do they undergo uniform mutations worldwide. The virus would likely undergo a variety of mutations, some beneficial and some detrimental, as described below.

Virus Mutations and Their Impact

Viruses mutate randomly due to errors during replication. These mutations can either improve the virus's ability to infect a host, become more contagious, or may weaken the virus. Mutations that make the virus less lethal but more highly contagious are generally advantageous for the virus as it increases the chance of spreading without depleting the host population too quickly. Conversely, mutations that make the virus highly lethal often result in a faster extinction of the virus as it kills the host too quickly and reduces its ability to spread.

Complicating matters further is the fact that such a virus would need to achieve a coordinated, universal mutation, which is practically impossible in real-world scenarios. The global human population is diverse, spanning various geographical regions, ethnicities, and living conditions, making it nearly impossible for a virus to undergo the same type of mutation in every single person worldwide. Even if such a coordinated mutation were to occur, the entire world's population would likely suffer a significant loss, as is often depicted in apocalyptic scenarios.

Real-World Analogies: HIV/AIDS and COVID-19

While a virus with a prolonged incubation period and rapid lethality is not feasible, it's worth considering a different type of virus that primarily remains asymptomatic for years but becomes extremely deadly. For instance, HIV, or AIDS, fits this description. HIV does not typically present symptoms until an advanced stage, over several years, leading to massive mortality when symptoms finally manifest. Whether one catches HIV is also relatively rare, with the main transmission routes being through blood transfusions or unprotected sex, and the risk is even lower for these scenarios.

Thinking about a nightmare fuel or a doomsday scenario, we can imagine a disease that mirrors HIV but is transmitted like the novel coronavirus (SARS-CoV-2). Such a virus might remain latent for years, then suddenly activate and become highly lethal. Possible transmission routes could include airborne particles (droplets), touching surfaces (like door handles in urban areas), or even the plumbing systems within quarantined buildings, as depicted in the Hong Kong scenario of the above-mentioned game.

Conclusion

In summary, while a virus with a one-year incubation period and rapid lethality is highly improbable due to the complexity and randomness of viral mutations, a virus with a prolonged asymptomatic period followed by fatal symptoms is indeed a possibility. Factors such as the current healthcare landscape and the ability of the virus to find new hosts play significant roles in this scenario. Understanding these factors can help us better prepare for potential outbreaks and pandemics in the future.